1. Field of the Invention
This invention relates to improvements for an apparatus for a door latch.
2. Description of Related Art
Prior to the present invention, most door latches required the user to twist and rotate a door knob or handle around an axis. Existing Push-Pull type door mechanisms typically require a separate device such as mount with paddles to actuate the mechanism. These paddles can only be oriented in one specific direction at a time and force the user to position their hand to match the orientation of the paddle or handle to open the door.
In all spring loaded push-pull designs, the act of pushing or pulling to release the door causes friction between the sliding surfaces in the mechanism including between the bolt and strike plate. As the mechanism is actuated, the spring force increases, which in turn increases friction within the mechanism and bolt and strike plate, so that the user has to apply continually increasing force until the bolt releases from the strike plate.
Current designs are complex mechanisms that take more force to operate due to the number of sliding surfaces and the additional pivot located within the separate paddle/handle mechanism.
Some disadvantages of the design reflected in U.S. Pat. No. 7,607,704: the mechanism starts off with a mechanical disadvantage meaning more force is spent pushing on the door, which increases friction between the bolt and strike plate than is spent drawing the bolt back to release the door. In the design as shown, forces that are exerted by the user beyond the limit of travel of the mechanism create a moment on the screws that mount the bolt housing to the door.
From the preceding descriptions, it is apparent that the devices currently being used have significant disadvantages. Thus, important aspects of the technology used in the field of invention remain amenable to useful refinement.